Error when baking molecular script addon
The molecular addon (and the cube surfer from the same author) are not pure python addons, they also use a shared library that needs to be compiled and located in the same addon folder.

For windows this will be cmolcore.pyd which needs to be in C:\Users\&lt;user&gt;\AppData\Roaming\Blender Foundation\Blender\2.7.3\scripts\addons\molecular\ If the library file is there then you may have downloaded the 64bit version by mistake.

If you still can't get it running you may need to compile a version specific to your machine. You can find the source files on github, read the cython docs for how and if you have any problems compiling ask for help on stackoverflow.